Edward Snowden participated in the Harvard event from Moscow.“I don’t want to turn this into a point-by-point, Oxford-style debate,” said DeLong, who attended physics lectures in same lecture hall when he was a Harvard student. “But I think it’s important to correct the record and not think of the NSA as doing things that were not authorized.”That didn’t mean he was ready to engage on every subject. When a participant in the symposium — organized by Harvard’s Institute for Applied Computational Science — asked who did authorize spying on US allies, DeLong evaded the question with the skill of a trained politician, essentially saying it was not for him to talk about.